Developing Mexican Silver-Zinc Production
Xtierra Inc. (TSXV | XAG) is a Toronto based and TSX Venture Exchange listed mineral exploration and development company focused on the development of precious and base metal projects located in the State of Zacatecas, Mexico.
Xtierra plans to become a mid-tier producer of silver and base metals through the development of its Bilbao deposit located in the Central Mexican Mineral Belt in the State of Zacatecas, as well as through exploration and acquisition opportunities.
BilbaoXtierra's primary project is the Bilbao silver-zinc-lead-copper deposit situated in the Panfilo Natera district of Zacatecas, approximately 50 km south of the state capital of Zacatecas where Xtierra is currently completing a bankable feasibility study.
In May 2011, Xtierra published a revised independent resource estimate, compliant with National Instrument 43‐101, for the Bilbao deposit of 10.62 million tonnes which represented a 6% increase in total metal content, as zinc equivalent, from 650,565 tonnes Zneq to 688,258 tonnes Zneq from the previous estimate (Feb. 2010).
In the indicated category, sulphide resources represent 50% of the resource, mixed oxide and sulphide resources represent 15% and oxide resources represent 35%. For the purpose of determining resources at various cut-off grades, zinc equivalent values were determined, based on the average LME metal prices during the 24 month period January 2009 to January 2011. Xtierra has recently (July 2012) completed a programme of infill drilling, the results of which will be incorporated in to a final resource estimate as part of the feasibility study.
Small-scale historic production from glory hole and shallow underground development in near surface oxide mineralization at Bilbao.
Feasibility Study Nearing Completion
Xtierra retained DRA Americas in 2010 to oversee and complete the Feasibility Study on the Bilbao project which is comprised of metallurgical test work on the oxide, mixed and sulphide mineralization, geotechnical studies, hydrogeological studies, topographic surveys, mine planning and engineering studies, capital and operating costs and environmental and permitting studies.
During Q1 2012, work was conducted in developing a detailed mine plan for the underground areas, including evaluation of underground mining methods and design of an access ramp and necessary stope development. Xtierra has retained Golder Associates to advise on tailings disposal and related plant design work.
In order to optimize water consumption, reduce and simplify the design of the tailings disposal impoundment infrastructure and generate material for back filling of underground stopes, production of paste tailings is being considered.
Geotechnical, hydrogeology and electrical power distribution infrastructure studies have been completed and are under review by DRA.
Based on the metallurgical results received to date it is expected that the Feasibility Study will recommend the initial development of an underground mine and the processing of the sulphide and transition resources. The development of the open pit mine and processing of the oxide ore would be deferred until later in the mine life, subject to further metallurgical optimization of the oxide process flow sheet and open pit resource optimization.
Items to be completed in the Feasibility Study include final optimization of the sulphide and transition ore process flow sheet to possibly include the production of a copper concentrate in addition to lead and zinc concentrates, completion of underground mine plans and schedules, completion of tailing disposal plans, completion of a final EIA, securing surface and water rights, and finalization of operating and capital cost estimates.
Xtierra holds approximately 13,000 ha of exploration licenses in the surrounding Panfilo Natera mining district as well as its La Laguna silver-gold tailings project and its El Dorado gold project.
La Laguna project has a bankable feasibility study completed by Micon International which contains an estimated mineral reserve of 6,799,000 t, containing an average of 57.92 g/t silver, 0.31 g/t gold and 328.92 g/t mercury.
El Dorado Gold Project - Xtierra commenced initial drilling of its gold project located in the historic Pinos gold district of Zacatecas in early January 2010.
La Laguna Pedernalillo tailings resource
Eldorado gold project, Pinos